package com.nkang.kxmoment.util;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import com.nkang.kxmoment.util.Constants;
public class SignUtil {
 
    private static String token = Constants.WECHAT_TOKEN;
    
    public static boolean checkSignature(String signature, String timestamp, String nonce) {  
        String[] arr = new String[] { token, timestamp, nonce };  

        Arrays.sort(arr);  
        String content=arr[0].concat(arr[1].concat(arr[2]));
        MessageDigest md = null;  
        String tmpStr = null;  
  
        try {  
            md = MessageDigest.getInstance("SHA-1");  
            byte[] digest = md.digest(content.toString().getBytes());  
            tmpStr = byteToStr(digest);  
        } catch (NoSuchAlgorithmException e) {  
            e.printStackTrace();  
        }  
  
        content = null;    
        return tmpStr != null ? tmpStr.equals(signature.toUpperCase()) : false;  
    }  

    public static String byteToStr(byte[] byteArray) {  
        String strDigest = "";  
        for (int i = 0; i < byteArray.length; i++) {  
            strDigest += byteToHexStr(byteArray[i]);  
        }  
        return strDigest;  
    }  
  

    public static String byteToHexStr(byte mByte) {  
        char[] Digit = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };  
        char[] tempArr = new char[2];  
        tempArr[0] = Digit[(mByte >>> 4) & 0X0F];  
        tempArr[1] = Digit[mByte & 0X0F];  
  
        String s = new String(tempArr);  
        return s;  
    }  
}
